Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pilated Neisseria gonorrhoeae of colony type 1 (T1) and non-pilated bacteria of colony type 4 (T4) were observed by transmission (TEM) and scanning electron microscopy (SEM). No pili were observed on T4 gonogocci, but two types of pili--straight, type a, and bent, type b--were seen on T1 by TEM. When incubated with human sperum and examined by either TEM or SEM, T1 gonococci were seen to attach by individual pili, by several pili wound together as a rope, or by direct contact. Gonococci from T4 colonies attached only by direct contact. Treatment with typsin (1 mg/ml) damaged or removed pili from gonococci. After incubation with trypsin, attachment of pilated gonococci to sperm was decreased significantly, but such treatment did not affect attachment of non-pilated gonococci. Incubation of gonococci from either colony type in 0.1 mmol/l ferric nitrate, followed by incubation with sperm, significantly increased attachment of only T4 bacteria. No pili were seen on T4 gonococci treated with ferric nitrate; thus, it appears that factors other than pili alone are concerned in attachment of these gonococci to sperm.
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PMID:Attachment of Neisseria gonorrhoeae to human sperm. Microscopical study of trypsin and iron. 3 83

The effects of various treatments on erythrocyte shape, surface, cell coat and calcium binding sites have been investigated by means of high voltage electron microscopy (HVM), scanning electron microscopy (SEM) and conventional electron microscopy (TEM). Papain caused the formation of small blisters within the cellular surface as well as crenation and 'budding' of the erythrocytes. After neuraminidase treatment, long filaments were observed to radiate from the surface of the erythrocyte. The other enzymes investigated, RNA'se DNA'se, phospholipase, protease and trypsin, produced no demonstrable effect on the cellular structure, nor (with the possible exception of trypsin) on the cell coat as seen by subsequent staining with ruthenium red. Putative calcium binding sites on and in the erythrocyte membrane were demonstrated. Following incubation with radioactive calcium, activity was found in the erythrocyte membranes. Calcium binding could be reduced by prior treatment of the erythrocyte with EDTA, neuraminidase, and to a lesser extent, by papain and trypsin. Other enzymes had no demonstrable effect. Stored erythrocytes showed a progressive diminution in calcium binding over a period of up to 4 weeks.
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PMID:Localization and role of calcium in the erythrocyte coat: effects of enzymes and storage. 72 71

The recent interest for highly sophisticated techniques of dental tissue preparation aiming to display very particular structures, moved the AA. to improve the literature suggestions. In particular they made TEM and SEM observations of transitional zones between healthy and normal pulp and dentin after decalcification and trypsin at different concentrations treatment. The images obtained draw in the attention the study facilities of a technique that really removes all the non collagenic material. The data obtained in the pericellular zones also allowed some interventions in the recent literature discussion about inter-odontoblastic fibres.
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PMID:[An ultrastructural study of the fibrillary component of dental tissues]. 193 74

Human deciduous teeth undergoing physiologic root resorption were extracted and fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and transmission (TEM) electron microscopy, and for acid (ACPase) and alkaline phosphatase (ALPase) cytochemistry. The resorbant organ, rich in odontoclasts, cementoblasts, fibroblasts, and macrophages, formed prominent resorption lacunae in root dentin. SEM observations of resorption lacunae treated with trypsin solution showed islands of newly-formed cementum matrix in part of the resorbing dentin surfaces. Such cementum consisted of bundles of densely-arranged collagen fibrils and, in part, contained forming cementocytic lacunae and canaliculi. Active cementoblasts adjacent to odontoclasts on resorbing dentin surfaces showed cuboidal outlines and were characterized by the presence of numerous cisterns of rough endoplasmic reticulum, well-developed Golgi complexes, secretion granules, and many mitochondria. They sometimes formed a thin layer of cementoid and/or cementum matrix upon the resorbing dentin surface. These cementoblasts had ACPase-positive lysosomes in the cell bodies and exhibited intense ALPase activity along the plasma membranes of whole cell surfaces. These results suggest that, during root resorption, 1) active cementoblasts are present adjacent to active odontoclasts and 2) these cementoblasts are involved in remodeling the resorbing dentin surfaces.
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PMID:Possible role of cementoblasts in the resorbant organ of human deciduous teeth during root resorption. 214 74

In many experimental models of skeletal muscle damage and in human muscle disease, empty basement membrane tubes remain following the destruction of muscle fibres. In the present study we test the hypothesis that the empty basement membrane tubes play an essential role in the orientation of regenerating muscle fibres. Two groups of 15 Wistar rats were used. In one group, aqueous barium chloride (BaCl2) solution was injected into the right quadriceps muscle; in the other group, freshly prepared 2% trypsin solution was similarly injected. The different stages of muscle cell necrosis and regeneration were observed by histology, by immunofluorescence using an anti-basement membrane antibody, and by transmission (TEM) and scanning electron microscopy (SEM) in animals killed 1-77 days following injection. Although there was muscle fibre necrosis at sites of BaCl2 injection, empty basement membrane tubes were well preserved. Myoblasts grew along the empty basement membrane tubes and by 77 days, the regenerated muscle fibres at the site of the injection were well oriented. Trypsin not only destroyed muscle fibres but also destroyed the basement membrane tubes; in the early stages of regeneration the myoblasts were disorientated but by 77 days, regeneration was comparable to that seen in the barium chloride injected muscle. The results of this study suggest that preservation of empty basement membrane tubes is not essential for the orientation of regenerating myoblasts in skeletal muscle.
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PMID:Role of the basement membrane in the regeneration of skeletal muscle. 240 30

At the level of ultrastructure, basement membranes (BMs) are usually described as thin layers of extracellular matrix comprised of an interwoven mat of fine 3-4 nm fibrils embedded in a granular matrix. In order to improve the resolution of the fibrillar components, we have carried out TEM studies on human glomerular BMs (GBMs) made acellular by sequential detergent solubilization. Some GBMs were pretreated with pronase, trypsin, or pepsin for 30 min to 72 h prior to preparation for microscopy. Our study shows that irrespective of which enzyme is employed, background granular matrix is first solubilized leaving a three dimensional fibrillar network comprised of 3-8 nm fibrils. Larger 7-8 nm fibrils are concentrated near subepithelial portions of the GBM and are most resistant to proteolysis. Smaller 3-4 nm fibrils are located primarily subjacent to endothelium and mesangial cells and are more protease-sensitive. An unexpected finding in pepsinized samples was a quasi-hexagonal fibrillocrystalline structure associated with mesangial matrix and subendothelial portions of the GBM. These data suggest that intrinsic fibrillar components of human GBMs are heterogeneously distributed throughout the thickness of their laminae densae. We speculate that the network consists of type IV collagen and that the hexagonal crystals may represent type VI or some previously unreported BM collagen type.
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PMID:Intrinsic fibrillar components of human glomerular basement membranes: a TEM analysis following proteolytic dissection. 249 69

The complete amino acid sequence of the p453-plasmid-mediated PIT-2 beta-lactamase (SHV-1) was determined. The protein contains 265 residues. Peptides resulting from digestions with trypsin, Staphylococcus aureus V8 proteinase, chymotrypsin and Lys-C proteinase and cleavage with CNBr were separated and purified by using reverse-phase h.p.l.c. The amino acid sequence of each peptide was manually determined with the dimethylaminoazobenzene isothiocyanate/phenyl isothiocyanate double-coupling method. The primary structure of PIT-2 beta-lactamase was compared with those of two closely related enzymes, namely TEM-1 beta-lactamase and the beta-lactamase of Klebsiella pneumoniae strain LEN-1. The PIT-2 beta-lactamase amino acid sequence was strongly retained, with respectively 68% and 88% homology. Thus PIT-2 enzyme could represent an evolutionary step between a chromosomally encoded beta-lactamase and the plasmid-mediated TEM beta-lactamases.
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PMID:Complete amino acid sequence of p453-plasmid-mediated PIT-2 beta-lactamase (SHV-1). 326 Apr 90

A protein fraction (60-F), obtained from cell-free extract of living hemolytic streptococcus, Su-strain, by 50-60% saturation with ammonium sulfate, inhibited the de novo synthesis of nucleic acids and proteins in Ehrlich ascites carcinoma (EAC) cells. 60-F released RNA but not DNA from EAC cells. This cytotoxic or cytolytic effect of 60-F was substantiated morphologically by scanning and transmission electron microscopic (SEM and TEM) observations, showing that 60-F induced cellular changes such as a loss of microvilli, bleb formation, cell deformity and partial gap of cell membrane in EAC cells. In addition, it was found that 60-F was more stable in RPMI-1640 medium supplemented with fetal calf serum than in other various media examined and was sensitive to temperature, pH changes and trypsin digestion.
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PMID:Biochemical and electron microscopic observations of cytotoxic effect of a fraction from hemolytic streptococcus on Ehrlich ascites carcinoma cells. 618 69

The blebbed surface morphology produced by trypsinisation of Chinese hamster ovary cells is subsequently reorganized to a microvillous topography, even in the continued presence of trypsin. Scanning and transmission electron microscope (SEM and TEM) observations of this transition showed the initial formation of a "crown' of densely clustered microvilli at one pole of the cell. At the periphery of this region the blebs coalesced to form ridges which subsequently extended over the entire cell surface. Long, and occasionally branched microvilli were generated from the ridges. Large numbers of membrane associated vesicles were also characteristic of these areas of surface reorganisation.
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PMID:Conversion of blebs to microvilli: cell surface reorganisation after trypsin. 732 17

The lamina basilaris of guinea pig cochlea was studied with SEM after trypsin treatment, and with TEM of resin sections and deep-etching replicas. The lamina consists of radial, evenly compacted filaments in the zona arcuata, and radial, discretely bundled filaments in the zona pectinata. In both zones, elementary filaments measured about 12 nm in thickness on the replica. The filaments formed more or less irregular passing bridges with each other and, eventually, a three-dimensional network which was continuous with the basement membrane under the supporting cells.
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PMID:Fine structure of the lamina basilaris of guinea pig cochlea. 829 28


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